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June 2015 Online Print Version
International Journal of latest Research in Engineering and Technology (IJLRET) Print Version, Volume 01, Issue 01 June 2015 Edition ISSN 2454-5031
IJLRET www.ijlret.com International Journal of latest Research in Engineering and Technology (IJLRET)
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International Journal of latest Research in Engineering and Technology (IJLRET)
Volume 01, Issue 01 June 2015 Edition ISSN 2454-5031
Contents A two-switch multi-input step-up DC/DC converter for PV systems………………………………………………………………………01 Mahdi Elmi, Mohamad Reza Banaei…………………………………………………………………………………………………………01 CFD Analysis and Experimental Validation of Ethanol Diesel Blend in CI Engine……………………………………………………10 Mathew Varghese T, Gavudhama Karunanidhi S…………………………….……………………………………………………..10 The Restoration of Shadorvan Dam-Bridge, Cultural & Historical Landmark of Shooshtar…………………………………….15 Taleb-Mash’hadi, Fereshteh, Daneshpour , Abdul-hadi, Laghai, Hassan-Ali…………………………………………..15 Sliding mode control of Vienna rectifier with output voltage control……………………………………………………………………23 Rouzbeh Reza Ahrabi, Mehdi Elmi, Mohammad Reza Banaei…………………………………………………………………23 Basics Of Kalman Filter And Position Estimation Of Front Wheel Automatic Steered Robot Car……………………………30 Muqri Muzammil, Prashant Bhopal, Yogesh Jain……………………………………………………………………………………30
International Journal of Latest Research in Engineering and Technology (IJLRET)
ISSN: 2454-5031(Online)
www.ijlret.com ǁ Volume 1 Issue 1 ǁ June 2015 ǁ PP.01-09
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A two-switch multi-input step-up DC/DC converter for PV
systems
Mahdi Elmi1, Mohamad Reza Banaei
2
1 Department of Electrical Engineering, Azarbaijan Shahid Madani University, Tabriz, Iran 2 Department of Electrical Engineering, Azarbaijan Shahid Madani University, Tabriz, Iran
Abstract— This study presents a new two-switch multi-input high step-up DC/DC converter. A coupled
inductor is used to enhance the voltage gain. Having a bidirectional port makes the converter suitable for
applications in need of battery such as stand-alone photovoltaic (PV) systems. As a result, the proposed
converter has the merits of integrating two power sources along with boosting the input voltage. Furthermore, in
comparison with typical three-port DC/DC converters which utilize three switches, the presented converter
employ only two switches to control the converter. Hence, cost and size of the structure is reduced. In order to
verify the performance of the converter, simulation results are taken and depicted.
Keywords— multi-input, DC/DC converter, high step-up, stand-alone PV systems, maximum power point
tracking (MPPT) algorithm.
I. INTRODUCTION Currently, a great proportion of electricity used around the world is generated by burning fossil fuels such as gas
and coal. This makes the electricity sector one of the biggest contributors to greenhouse emissions. On the other
hand, the sources of fossil fuels are limited and going to be used up completely in near future. Aforementioned
problems along with capability of renewable energy resources in generating electricity have lead the
governments and researchers to increase the contribution of them in electric production. Among these resources,
PV systems have noticeable features including noiseless function, no pollution, vast scale availability and low
maintenance cost [1]. However, intermittent feature of PVs is one of their main drawbacks. Hence, PV systems
are accompanied with an energy storage system (ESS) to balance the power between PV modules and load in
stand-alone renewable power system applications [2]. One feature that must be taken into account in designing
the interface converter for PV systems is the bidirectional power flow capability of storage element port. In
conventional systems, multiple individual converters have been used for each power supply (either
unidirectional or bidirectional). Nowadays, compared to typical structures, multi-input converters (MICs) offer a
compact converter with centralized control, higher reliability and efficacy, lower size and cost reduction [3]. In
recent literature, a number of works have been reported in designing a compact converter which could integrate
two power supplies to the utility grid or load [4-5]. A compact three port DC-DC converter is studied in [4]. One
of the merits of the presented converter is having a bidirectional port which makes it suitable for applications in
need of battery. Moreover, the number of utilized elements is reduced in comparison with conventional
structures. However, low voltage ratio of the converter makes it unsuitable in high voltage gain applications. In
[5], an isolated three-phase high step-up DC-DC converter is used for integrating renewable energy resources
into the grid or load. By the use of three-phase high frequency transformer, high voltage gain is achieved. The
converter utilizes only three switches which results in a higher efficiency. However, another converter is needed
to connect the battery to the DC bus. A compact two-input converter is proposed for standalone PV systems in
[6]. Moreover, high voltage gain of the converter makes the converter suitable for low input voltage
applications. However, the high number of semiconductors and passive elements reduce the efficiency.
This paper presents a novel two-switch high step-up multi-port DC-DC converter to integrate stand-alone
PV system and battery unit into the DC bus. Compared to conventional multi-ports which use at least three
switches to hybridize a power source and a battery, the proposed converter has only two switches. Hence, cost
and size of the converter is significantly reduced. Meanwhile, high step-up capability of the converter makes it a
promising converter for power supplies with low output voltage, such as PVs. Performance of the converter in
three states including no battery, battery charging and battery discharging is analyzed. The rest of the paper is
devoted as followings. In the next section, analysis of the converter is given. Employed power management
method is described in Section III. In section IV, simulation results are depicted. Finally, section V concludes
the whole paper.
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II. OPERATION PRINCIPLES A) Circuit Principles
The structure of proposed converter is shown in Fig. 1. The circuit consists of two power switches, five
diodes, three capacitors and one coupled inductor. Vi is the primary input and battery is assumed as second
input. Coupled inductor is modeled as magnetize inductor Lm, leakage inductor Lk and an ideal transformer
N2/N1. In order to simplify the circuit analysis, following assumptions are taken:
1) The proposed converter is analyzed in continuous conduction mode (CCM).
2) Capacitors C1, C2 and Co are large enough and voltage across them are considered as constant voltages.
3) Turn ratio of transformer N2/N1 is assumed as n.
4) The power switches and diodes are ideal.
5) The coupling coefficient of the couple inductor k equals to Lm/(Lm+Lk).
Fig. 1. Proposed Converter’s Circuit Structure
B) Operation States
The proposed converter can operate in three different states which are described in followings:
1) Single input: Main power source supplies the load and battery is not connected.
2) Battery charging: Main power source supplies the load and battery is charged.
3) Battery discharging: Main power source supplies the load and battery is discharged.
First State (Single input): In this state, Vi furnishes the load without the battery. This state consists of five
operation modes (Fig. 2.).
Operation mode I [t0-t1]: This operation mode begins at t0 by turning switches S1 and S2 on. Diode D4
conducts and other four diodes are off. The load is supplied by output capacitor Co and input source charges the
coupled inductor. This mode ends when the current of secondary windings of coupled inductor reaches zero.
Operation mode II [t1-t2]: This operation mode begins at t1, when diode D4 turns off with ZCS. During this
state, current of leakage inductor is bigger than current of magnetizing inductor. Diode D5 is on and others are
off. The load is supplied by output capacitor Co and input source charges the coupled inductor. This mode ends
when switches S1 and S2 are turned off.
Operation mode III [t2-t3]: By turning switches S1 and S2 off, diode D2 will be turned on. Since the currents
of primary and secondary sides of coupled inductor is not equal, clamp diode D2 conducts and the stored energy
in leakage inductor is transmitted to the output load. During this mode, diode D5 conducts and diodes D1, D3 and
D4 remain off. This mode ends when the current of secondary windings reaches zero.
Operation mode IV [t3-t4]: in this mode, switches S1 and S2 are off and diodes D1, D2 and D3 conduct. Diodes
D4 and D5 are off. During this mode stored energy in capacitor C2 is transmitted to the output. This mode ends
when switch S1is turned on.
Operation mode V [t4-t5]: This mode begins when diode D2 turns off with ZCS and continues until switches
S1 and S2 are turned on. Diodes D1, D2 and D4 are off. During this mode energy of input source, coupled
inductor and capacitor C2 is transmitted to the output load and capacitor.
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Fig. 2. Operation states of first state. (a) [t0-t1], (b) [t1-t2], (c) [t3-t4], (d) [t4-t5] and (e) [t5-t6]
Typical waveforms of first state are depicted in Fig.3.
Fig. 3.Wave forms of first state
Second State (Battery charging): In this state, main power source supplies the load and charges the battery.
This state consists of six operation modes (Fig. 4.).
Operation mode I [t0-t1]: This mode begins by turning switch S2 on. During this mode, diodes D1 and D4 are
on and diodes D2, D3 and D5 are off. Meanwhile, input source charges the battery and output capacitor CO
charges the load. Secondary side of coupled inductor charges capacitor C1. This mode ends when current of
secondary side of coupled inductor reaches zero.
Operation mode II [t1-t2]: This mode begins when diode D4 turns off with ZCS. In this mode the currents of
Lk and Lm are equal and coupled inductor is charged. During this mode switch S2 and diode D1 are on and switch
S1 and diodes D2, D3, D4 and D5 are off. This mode ends by turning S1 on.
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Operation mode III [t2-t3]: This mode begins at t3 by turning switch S1 on. Diodes D1, D2, D3 and D4 are off.
Input source charges the coupled inductor and output capacitor CO charges the load. Diode D5 conducts and
capacitors C1 and C2 are charged by the secondary side of coupled inductor.
Operation mode IV [t3-t4]: By turning switches S1 and S2 off, diode D2 will be turned on. Since the currents
of primary and secondary sides of coupled inductor is not equal, clamp diode D2 conducts and the stored energy
in
(a)
(b)
(c)
(d)
(e)
(f)
Fig. 4 Operation modes of second state. (a) [t0-t1], (b) [t1-
t2], (c) [t2-t3], (d) [t3-t4], (e) [t4-t5] and (f) [t5-t6]
leakage inductor is transmitted to the output load. During this mode, diode D5 conducts and diodes D1, D3 and
D4 remain off. This mode ends when the current of secondary windings reaches zero.
Operation mode V [t4-t5]: in this mode, switches S1 and S2 are off and diodes D1, D2 and D3 conduct. Diodes
D4 and D5 are off. During this mode stored energy in capacitor C2 is transmitted to the output. This mode ends
when switch S1is turned on.
A two-switch multi-input step-up DC/DC converter for PV systems
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Operation mode VI [t5-t6]: This mode begins when diode D2 turns off with ZCS and continues until switches
S1 and S2 are turned on. Diodes D1, D2 and D4 are off. During this mode energy of input source, coupled
inductor and capacitor C2 is transmitted to the output load and capacitor. Operation wave forms of second state
are depicted in Fig. 6.
Fig. 5. Wave forms of second state
Third State (battery discharging): In this state, main power source and the battery supply the load and the
battery is being discharged. This state consists of seven operation modes (Fig. 6.).
Operation mode I [t0-t1]: First mode begins by turning switch S1 on. Diodes D3 and D4 are on and diodes D1,
D2 and D5 are off. During this mode, stored energy in the battery, energy of input source, coupled inductor and
capacitor C2 are transmitted to the output load and V capacitor.
Operation mode II [t1-t2]: Second operation mode begins when diode D4 turns off with ZCS. During this
mode current of magnetizing inductor is bigger than the current of leakage inductor. During this mode switch S1
and diode D3 are on and switch S2 and diodes D1, D2, D4 and D5 are off. Meanwhile energy of input source,
the battery, coupled inductor and capacitor C2 is transmitted to the output load and capacitor.
Operation mode III [t2-t3]: Third operation mode starts when switch S1 and S2 are turned on. During this
mode diode D4 is still on and the other diodes are off. In this mode, input power source charge the coupled
inductor. And output capacitor Co charges the load. Secondary side of coupled inductor charges the capacitor
C1.
Operation mode I [t3-t4]: This mode begins when diode D4 turns off with ZCS. During this mode, both
switches are on and diodes D1, D2, D3 and D4 are off. Meanwhile, the current of leakage inductor is bigger
than magnetizing inductor and the current flowing through the secondary side of the coupled inductor is
negative.
Operation mode V [t4-t5]: By turning switches S1 and S2 off, diode D2 will be turned on. Since the currents of
primary and secondary sides of coupled inductor is not equal, clamp diode D2 conducts and the stored energy in
A two-switch multi-input step-up DC/DC converter for PV systems
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leakage inductor is transmitted to the output load. During this mode, diode D5 conducts and diodes D1, D3 and
D4 remain off. This mode ends when the current of secondary windings reaches zero.
Operation mode VI [t5-t6]: in this mode, switches S1 and S2 are off and diodes D1, D2 and D3 conduct. Diodes
D4 and D5 are off. During this mode stored energy in capacitor C2 is transmitted to the output. This mode ends
when switch S1is turned on.
Operation mode VII [t6-t7]: This mode begins when diode D2 turns off with ZCS and continues until
switches S1 and S2 are turned on. Diodes D1, D2 and D4 are off. During this mode energy of input source,
coupled inductor and capacitor C2 is transmitted to the output load and capacitor.
(a)
(b)
(c)
(d)
(e)
(f)
(g)
Fig. 6 Operation states twos‟ modes. (a) [t0-t1], (b) [t1-t2],
(c) [t2-t3], (d) [t3-t4], (e) [t4-t5], (f) [t5-t6] and (g) [t6-t7]
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Operation wave forms of third state are depicted in Fig. 7.
Fig. 7 Wave forms of third state
C) Steady-state Analysis of Proposed Converter In order to simplify the analysis of the converter, in addition to assumptions made in pervious section, the
followings are also made:
Leakage inductance of coupled inductor Lk is ignored.
Ds1 and Ds2 represent the duty ratios of switches S1 and S2, respectively.
A. First state (Single input)
Voltage gain of the converter in first state can be calculated as follows:
1
1V DC
n nDM
D
(1)
B. Second state(Battery charging)
Using the same procedure for this state, output voltage of the converter in second state can be calculated as
follows:
2 2 1
2
(1 ) (2 1)( )
1
S in S S BO
S
n nD V n D D VV
D
(2)
C. Third state(Battery discharging)
Likewise, output voltage of the converter in third state can be calculated as follows:
1 1 2
1
(2 1)(1 ) ( )
1
S in S S B
O
S
nn nD V D D V
nVD
(3)
III. MAXIMUM POWER POINT TRACKING (MPPT) METHOD The other main disadvantage of PV systems is that the efficiency of energy conversion is low at present. In
order to enhance the overall efficiency of system and reduce the cost of energy, it is important to make the PV
system work in MPP. In literature, different procedures have been addressed by researchers to achieve MPPT
[7-9]. Static optimization algorithms such as Perturb and observe (P&O) algorithm [7], incremental conductance
algorithm [8] and ripple correlation control (RCC) algorithm [9] have been discussed and presented in recent
A two-switch multi-input step-up DC/DC converter for PV systems
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researches. Simple programming and implementation, and low computation have made the P&O method a
practical and widely used scheme among other schemes. However, MPPT methods based on static optimization
have slower convergence in comparison with dynamic MPPT controls.
IV. SIMULATION RESULTS The proposed system is investigated in MATLAB/SIMULINK. The specifications of the circuit are given in Tables
I. TABLE I
SPECIFICATIONS OF THE PROPOSED CONVERTER
Specifications Values
Input voltage (Vin) 40 V
Battery voltage (VB) 12 V
Output voltage (Vout)
1st state:305 V
2nd state:290 V
3rd state:315 V
Switching frequency (fs) 50 kHz
Coupled inductor
LK: 1 μH, Lm: 200 μH
NS/NP=2
Output capacitor (Co) 220 μF
Load (RL) 3.2 Ω
Output voltage in three different stages is depicted in Fig. 8. Input current and current flowing through the
battery bank are illustrated in Fig. 9 and 10, respectively. All figures are divided into three parts. In first part,
battery is not used. In second part, battery is charged and in the last part, battery is discharged. Fig. 10 shows the
current flowing through the battery bank. In first part, it has zero value, in second and third parts, it has a
positive and negative average, respectively.
V. CONCLUSION In this paper, a new two-switch multi-input high step-up DC/DC converter was proposed and studied. The
converter is suitable for domestic and industrial applications such as stand-alone PV systems, shipboard system,
and hybrid electric vehicles. Analysis of the converter was given for three operational modes including no
battery, battery charging, and battery discharging. Compared to the typical dual input DC/DC converters which
use three switches, the presented converter utilizes only two switches. Hence the cost and size of the converter is
significantly reduced. Moreover, simulation results validated the promising performance of the converter.
References [1] Nejabatkhah, F.; Danyali, S.; Hosseini, S.H.; Sabahi, M.; Niapour, S.M., "Modeling and Control of a New
Three-Input DC–DC Boost Converter for Hybrid PV/FC/Battery Power System," Power Electronics, IEEE
Transactions on , vol.27, no.5, pp.2309,2324, May 2012
[2] Hongfei Wu; Runruo Chen; Junjun Zhang; Yan Xing; Haibing Hu; Hongjuan Ge, "A Family of Three-Port
Half-Bridge Converters for a Stand-Alone Renewable Power System," Power Electronics, IEEE
Transactions on , vol.26, no.9, pp.2697,2706, Sept. 201
[3] Danyali, S.; Hosseini, S.H.; Gharehpetian, G.B., "New Extendable Single-Stage Multi-input DC–DC/AC
Boost Converter," Power Electronics, IEEE Transactions on , vol.29, no.2, pp.775,788, Feb. 2014
[4] Rong-Jong Wai; Chung-You Lin; Bo-Han Chen, "High-Efficiency DC–DC Converter With Two Input
Power Sources," Power Electronics, IEEE Transactions on , vol.27, no.4, pp.1862,1875, April 2012
[5] Zhan Wang; Hui Li, "An Integrated Three-Port Bidirectional DC–DC Converter for PV Application on a
DC Distribution System," Power Electronics, IEEE Transactions on , vol.28, no.10, pp.4612,4624, Oct.
2013
[6] Li-Jhan Chien; Chien-Chih Chen; Jiann-Fuh Chen; Yi-Ping Hsieh, "Novel Three-Port Converter With
High-Voltage Gain," Power Electronics, IEEE Transactions on , vol.29, no.9, pp.4693,4703, Sept. 2014
[7] Roman,E., Alonso,R., Ibanez,P.,Elorduizapatarietxe,S., and Goitia,D.: „Intelligent PV module for grid-
connected PV systems‟,IEEE Trans. Ind. Electron., vol. 53, no. 4, pp. 1066–1073 2006
[8] Kwon,J. M., Nam,K. H., and Kwon,B. H.: “Photovoltaic power conditioning system with line connection”,
IEEE Trans. Ind. Electron., vol. 53, no. 4, pp. 1048–1054 2006
A two-switch multi-input step-up DC/DC converter for PV systems
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[9] S. L. Brunton, C. W. Rowley, S. R.Kulkarni, and C. Clarkson, “Maximum power point tracking for
photovoltaic optimization using ripple-based extremum seeking control,” IEEE Trans. Power Electron., vol.
25, no. 10,pp. 2531–2540, Oct. 2010.
International Journal of Latest Research in Engineering and Technology (IJLRET)
ISSN: 2454-5031(Online)
www.ijlret.com ǁ Volume 1 Issue 1 ǁ June 2015 ǁ PP.10-14
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CFD Analysis and Experimental Validation of Ethanol Diesel
Blend in CI Engine
Mathew Varghese T1, Gavudhama Karunanidhi S
2
1PG Scholar, MES College of Engineering, Kuttippuram, Kerala, Calicut University.
2Professor, Dept. of Mechanical Engineering, MES College of Engineering, Kuttippuram, Kerala
Abstract- This paper describes the CFD analysis and experimental validation for a blend of Ethanol and
Diesel in CI Engine. Ethanol is the alcohol found in alcoholic beverages but it also makes an effective motor
fuel. Since, ethanol possess low Cetane number it fails to auto ignite. In order to overcome this Diesel is
blended with Ethanol. Thus the Diesel will ignite and thus facilitate the Ethanol to start burning. In this work a
CFD model was created and the combustion analysis was carried out and the results were validated with
experimental data. The Ethanol and Diesel fuels were mixed in different proportions and they were injected to
the combustion chamber of a normal diesel engine. A single cylinder PC based VCR Engine was operated with
this Ethanol - Diesel blend in different concentrations and at various loads. The experiment was successful and
it showed that the Ethanol could be mixed with Diesel and could be injected without any engine modification.
The difference between CFD and the experimental results obtained was found within acceptable range.
Key Words: Ethanol, Diesel, CFD, Combustion
1.0.Introduction Fossil fuels are very important to us today. The increase on energy demand and increasing petroleum
price in the worldwide has increased the study of alternative fuels for internal combustion engines. Biodiesel and
DEB (Diesel – Ethanol Blend) have received much attention among these alternative fuels for Compression
Ignition (CI) diesel engines. Ethanol is one of a renewable fuel because we get it from raw materials such as
corn, sugar cane, sugar beets, molasses, cassava, waste biomass materials, sorghum, barley, maize, etc. Ethanol
can reduce the consumption of conventional gasoline and it has been successfully used to blend with gasoline
fuel as part of its alternative. However, due to the difference in chemical and physical properties, it has not been
commercially used yet. At present, significant investigations of the potential application of DEB on diesel
engine have been carried out.
Hansen et al. [1] found that the engine power decreases by about of 7 to 10 % and the brake thermal
efficiency increases by about of 2-3% at rated speed when investigated the Cummins engine performance with
15 % ED fuel In the same model engine with two and backgrounds.
blends. In the same model engine with two blends containing 10 % and 15 % ethanol, Kass et al. [2] tested the
torque output and got an approximate 8 % engine power reduction for both fuel blends. Huang et al. [3]
experimented by 10%, 20%, 25% and 30% ethanol-blended diesel fuels and examined the engine performance
and exhaust emissions of diesel engine. It results; increasing amount of ethanol in the blended fuels decreased
the brake thermal efficiencies. Also Rakopoulos et al. [4] studied the effects of ethanol blends with diesel fuel,
with 5% and 10% (v/v) on the performance and emissions of a turbocharged direct injection diesel engine. It
results the increasing the amount of ethanol in the fuel blend decreased the brake thermal efficiency and
increased the specific fuel consumption. Diesel fuel blended with ethanol up to 10 vol. % results [5–7] to
increase the engine efficiency, improve fuel economy and reduce its harmful emissions. Also yield a significant
reduction of carbon monoxide and nitrogen oxide [8] and particulate matter emissions [9, 10].
The major drawback of ethanol in diesel engines is less solubility of ethanol in diesel fuel and it leads
the phase separation and water tolerance in ethanol–diesel blend fuel. The phase separation can be prevented by
adding an emulsifier or co- solvent. Here by adding an emulsifier that acts to suspend small droplets of ethanol
within the diesel fuel and it usually requires heating and blending steps to generate the final blend. introduce a
more challenging dataset containing over 1800 annotated human images with a large range of pose variations
and backgrounds.
tolerance in ethanol–diesel blends. The phase separation can be prevented by adding an emulsifier or co-
solvent. Here by adding an emulsifier that acts to suspend small droplets of ethanol within the diesel fuel and it
CFD Analysis and Experimental Validation of Ethanol Diesel Blend in CI Engine
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usually requires heating and blending steps to generate the final blend. The properties of Diesel and Ethanol are
shown in Table 1. In this study we are using DEB15 (15% Ethanol and 85% Diesel)
Property Diesel Ethanol
Chemical formulae C12.35H21.76 C2H5OH
Composition in %
C
H
O
87.13
12.88
0
52.14
13.13
34.73
Density 820 786
Viscosity, Pa s 2.8 1.20
Latent heat, kJ/kg 375 840
Cetane number 48 6
Lower heating
value, MJ/kg
42.90 27.47
Table 1: Fuel Properties
2.0 CFD Modelling The combustion chamber is modelled and the analysis is carried out in detail using a CFD tool package
ANSYS FLUENT. A three dimensional periodic, in-cylinder, transient system for a direct injection diesel
engine is modelled by solving a set of governing equations from the conservation of mass, momentum, energy
and species theories. The Figure 1 shows the meshed geometry of the cylinder.
Figure 1: Meshed Cylinder Geometry
The in-cylinder parameters are
Connecting rod length: 140 mm
Bore: 80 mm
Crank radius: 55 mm
Crank shaft speed: 1500 rpm
In this present study the turbulent model selected is standard k- ε. This model of turbulence are of two-equation
model in which the solution of two separate transport equations allows the turbulent velocity and length scales to
be independently determined. It is a semi-empirical model, and the derivation of the model equations relies on
phenomenological
considerations and empiricism. The turbulent (or eddy) viscosity, μt, is computed by combining k and ε as
follows:
µt = ρ cµ
2k
The combustion model used is species transport with volumetric reactions. The inlet diffusion and diffusion
energy source is turned on. Eddy dissipation is used for turbulent chemistry interaction. This approach is based
on the solution of transport equations for species mass fractions, with the chemical reaction mechanism defined
by user. DPM fuel injection model is also used in this study.
3.0 Experimental Setup
The engine setup shown in Figure 1 used for experimental investigation is a single cylinder, Four
Stroke, Water cooled, PC based VCR Engine. It is connected to a eddy current type dynamometer for loading.
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The compression ratio can be changed without stopping the engine. The setup is provided with necessary
instrument for combustion pressure and crank angle measurement. These signals are interfaced to computer
through engine indicator for Pθ-PV diagrams. Provision is also made for interfacing air flow, fuel flow,
temperature and torque measurement. The setup has stand-alone panel box consisting of air box, two fuel tanks
for dual fuel test, fuel and air measuring unit
Figure 2: Experimental Setup
4.0 Result and Discussion This work is carried out in two stages the numerical CFD analysis and the experimental validation.
Each parameters are studied both numerically and experimentally with DEB15.
4.1 Combustion Peak Pressure
The peak pressure obtained by CFD analysis is 61 bar and experimentally the peak pressure is 58 bar.
This change in 3bar is almost negligible. The figure 3 shows the CFD result and figure 4 shows the experimental
result in VCR Engine.
Figure 3: P-θ CFD Result
Figure 4: P-θ Experimental Result
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4.2 Performance Characteristics
The performance characteristics of a single cylinder four stroke engine with DEB15 as fuel are
discussed below.
The figure 5 shows the variation of volumetric, brake thermal, indicated thermal and mechanical
efficiencies with brake power. The volumetric efficiency remains almost constant. The mechanical efficiency is
increasing with the increase in break power. The brake thermal efficiency is also increasing, but at higher load
there is a slight decrease can be noted. The indicated thermal efficiency shows an irregular variation with
increasing load. All these performance characteristics with DBE15 as fuel lies closer to that of diesel alone
operation.
Figure 5: Efficiencies vs Brake Power
4.3 Exhaust Gas Analysis
The exhaust gas analysis is done with ANSYS FLUENT. The figure 6 shows the NOx emission. The
mass fraction on NOx is 4.03e-05
.
Figure 6: NOx Emission
We can see the variation in the concentration of NOx from he above diagram. The concentration is more athe the
piston head and goes on decreasing upto the cylinder head.The mass fraction of soot is 6.43e-05
and CO emission
is 0.129. The figure 7 & 8 shows the soot and CO concentration inside the chamber.
Figure 7: Soot Concentration
CFD Analysis and Experimental Validation of Ethanol Diesel Blend in CI Engine
www.ijlret.com 14 | Page
Figure 8: CO Emission
The mass fraction of unburnt oxygen is noted as 2.52e-13
. This shows that almost complete combustion is taking
place and the injected fuel is fully utilized by the air inside the combustion chamber.
5.0 Conclusion
The numerical CFD analysis using ANSYS FLUENT and the experimental study with DBE15 is done.
The results are comparable which are obtained both numerically and experimentally. The peak pressure obtained
shows only a change in 3 bar pressure. And it is also seen that the ethanol diesel blend can be used in normal CI
engine without any engine modification. Thus the CFD tool ANSYS FLUENT is very reliable to predict the
combustion and emission characteristics.
Reference
[1] A.C. Hansen, Q. Zhang, "Engine durability evaluation with E-diesel". Paper Number: 036033. In: An
ASAE meeting presentation, Las Vegas, Nevada, USA, p. 13 ,July 2003.
[2] M.D. Kass, J.F.Thomas, J.M.Storey, N.Domingo, J.Wade, G. Kenreck, "Emissions from a 5.9 liter diesel
engine fueled with ethanol diesel blends". SAE Technical Paper 2001-01-2018 (SP-1632).
[3] J.Huang, Y. Wang, S. Li, A.P. Roskilly, Y. Hongdong, H. Li, "Experimental investigation on the
performance and emissions of a diesel engine fuelled with ethanol–diesel blends". Applied Thermal
Engineering, Vol. 29, No. 11–12, p.2484–90, 2009.
[4] D.C. Rakopoulos, C.D. Rakopoulos, E.C. Kakaras, E. Giakoumis, "Effect of ethanol–diesel fuel blends on
the engine performance and emissions of heavy duty DI diesel engine". Energy Conversion and
Management, Vol. 49, No. 11, p.3155–62, 2008.
[5] A.C. Hansen, R.H. Hornbaker, Q. Zhang, PWL. Lyne, "On-farm evaluation of diesel fuel oxygenated with
ethanol". Paper Number: 01-6173. In: An ASAE annual international meeting presentation, Sacramento,
California, USA, p. 17, 2001
[6] Ozer Can, smet elikten, Nazim Usta, "Effects of ethanol addition on performance and emissions of a
turbocharged indirect injection diesel engine running at different injection pressures". Energy Conversion
and Management, Vol. 45, 2429–40,2004.
[7] CY. Lin, JC. Huang, "An oxygenating additive for improving the performance and emission characteristics
of marine diesel engines". OCEAN Eng, Vol. 30, No. 13, 1699–715, 2003.
[8] EA. Ajav, B. Singh, TK. Bhattacharya, "Experimental study of some performance parameters of a constant
speed stationary diesel engine using ethanol–diesel blends as fuel". Biomass and Bioenergy, Vol.17, 357–
65, 1999.
[9] BQ. He, SJ. Shuai, JX. Wang, H. He, "The effect of ethanol blended diesel fuels on emissions from diesel
engine". Atmospheric Environment, Vol. 37, 4965–71, 2003. [10] A.C. Hansen, Q. Zhang, PWL. Lyne, "Ethanol–diesel fuel blends – a review". Bioresource Technology,
Vol. 96, p.277–85, 2005.
International Journal of Latest Research in Engineering and Technology (IJLRET)
ISSN: 2454-5031(Online)
www.ijlret.com ǁ Volume 1 Issue 1 ǁ June 2015 ǁ PP.15-22
www.ijlret.com 15 | Page
The Restoration of Shadorvan Dam-Bridge, Cultural & Historical
Landmark of Shooshtar
Taleb-Mash’hadi, Fereshteh MA in environmental design; Tehran University of Science & Research, Iran.
Daneshpour , Abdul-hadi PhD in urban design; Assisstant professor in the faculty of Urbanism, Tehran University of Science and
Technology, Tehran, Iran.
Laghai, Hassan-Ali PhD in urban Architecture, Associate professor in facultu of Environmental Design, Tehran University of
Science & Research, Iran.
Abstract- The cultural-historical landmark of Shooshtar has traversed a very long distant since the ancient era.
In fact it was the mutual corporation of history and nature that end up as a city like Shooshtar which is a
combination of both tradition and culture, emerged authentically in a wild natural way through time; and taking
the important historical landmarks under consideration, it is expected to become one significant tourism
attraction district. Retaining the sustainable aspects of the city, this research aims to restore connection between
natural and historical layers within the boundaries of natural city landscape restoration and its main purpose is to
provide a range of principles and solutions for a sustainable development, natural resources‟ conservation, and
retaining the historical sight of Shadorvan Bridge. Primary in this research, the issue and research method will be defined and afterwards, paraphrasing the
keywords of historical landmark and the principles of landmark restoration would lead toward a series of
principles for sustainable conservation in a historical landscape. Studying the site would be the next step and
following the landscape restoration rules, some issues such as points of strength & weakness, opportunities,
natural threats and vernacular culture will be concluded in a table, which all finally will indicate the criterions of
preservation to the historical landscape restoration of Shadorvan Bridge. The total conclusion would reveal that
the restoration of all the existing layers through the land and understanding the interconnections will guide us to
a comprehensive & general restoration ways of the similar landmarks. The fulfillment of this research is
achieved by means of descriptive-analytic method (with practical approach) in the context of library studies,
harvest field and documents review, detailed plans, summary information and applied access to general
principles.
Keywords: Tourism, Shadorvan Bridge, Shooshtar, region, cultural landmark
Introduction Every inch of this country has natural arena with historical, artful and cultural landmarks of Persian civilization
-the sites which have been constantly neglected; Meanwhile any plan for restoration would lack a
'comprehensive approach' toward their natural and historical values (Afshar Sistani, 1371: 574).
In a natural comtext, history is seen as ancient landmarks. “This dialogue between natural appearance
and cultural one, shall bring up a dynamic and prevalent process of change and evolution which guarantee the
sustainability and survival of a civilization. The prosperity of structural relation between nature and culture -
which have been achieved through time- and the maintenance of the proofs to the contemporary age, lead to
figure historical symbols with environmental values.” (Behbahani- Inanlou, 1379). Usually the failure in
removal of landscape obstacles and difficulties is not only related to the design disabilities, but also is directly
related to the insufficiency of data to offer a precise definition for site threats and strength and weakness points
(Mothloch, 2001: 286).
One of the most important discussions of current days within urban design management and
environmental design, is restoration of historical context management, which is declined for the weak points in
authority functioning strategies in historical landscape of Shadorvan. Hence, this issue is dedicated to
recognition of Shadorvan Bridge region –newly enlisted in UNESCO world heritage- as a historical-cultural site
to be the primary concern for its restoration process.
The Restoration of Shadorvan Dam-Bridge, Cultural & Historical Landmark of Shooshtar
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Subject and research necessity Historical squares or sites are to define credit and originality for a city and have artistic, cultural and historical
importance. These sites -containing the elegant and vernacular architecture of the region- “help to develop
historical knowledge or exist as a historical document” (Vinas, 1389: 43). Although urban historical sites play a
very important role in the architecture and originality of the city, but occasionally turn into an element without
any sign of fortime, due to paradoxical and inefficient ideas and theories. Here is a quotation from the Italian
critic and thinker, Cesare Brandi (1967):
“There is nothing intuitive and free-standing exterior as a „historical structure‟. What we call „historical
structure‟ is a concept defined in the relative connection of contemporary human with the structure built in the
past and gains significance accordingly. In another words, historical work is a phenomenon resulting as the way
human looks upon a work, which for the independent qualities lied in its essence and nature and also for all it
gained through long times, could be the subject of thoughtful discussions.” Therefor Shadorvan is considered as
a cultural landscape because “it compromises the unique features of the land and is a compound indication of
natural and humanistic works.” (UNESCO, 2009).
Shooshtar -3,538 Sqm- in located at the center of Khouzestan province. Having almost 100 aquatic
structures, Shooshtar is one of the most rare cities with old works of aquatic engineering and hydrology. Studies
in this region show disconnection and chaos among regional historical and natural continuity, therefor specific
conservation plans are considered to be mandatory.
Research Method The research method of this issue is descriptive-analytic method (with practical approach) in the
context of library studies, harvest field and documents review. In order to achieve a better cognition of the
historical-cultural landscape and their definitive and practical aspects, in the current research we have tried to
study the cultural landscape and the impressive factors upon its existence, and in order to provide and interpret
the case studies, we chose the harvest field method.
The ecology of historical landscape restoration What matters the most in restoring the landscape, is humanistic view along with the restoration of design nature.
In fact here we spot two different viewpoints toward the concept of restoration: One is by ecologists who
believe that “the scattered pieces of nature must be positioned back where they used to be”, and the second is the
viewpoint of landscape designers who mainly say that “the modification of a demolished landscape lies in
creating a place where could be reused by people.”
Here we have to mention that all the layers of existing values of the landscape -whether cultural or natural- must
be taken under consideration and being restored [UNESCO-ICOMOS, 2009: 8]. The most recent viewpoints on
landscape restoration suggest that the mere ecological study of natural environment and restoring the nature
within the landscape do not suffice. This approach, defined within the measures of landscape design, on one
hand aims to restoring the ecological bed of the region and on the other hand, -considering the cultural and
historical features of the region- also tries to restore the signs, symbols and artistic, cultural and historical
monuments (Figure 1).
“In fact by offering a humanistic design, the landscape restoration is looking for a way to ascend the quality of
landscape.” (Pour-Yousefzadeh, 1391: 6). And finally we should mention that restoring the landscape
compromises a wide range of ecological, social and cultural notions, and brings up solutions in order to restore
them on the basis of sustainable development purposes. Table 1 indicates the effects of natural landscape for
ecological study.
Figure 1: Shadorvan dom-bridge, Shooshtar, 2005. Source: Ali-Mohamad Chaharmahali‟s private atchive.
The Restoration of Shadorvan Dam-Bridge, Cultural & Historical Landmark of Shooshtar
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Table 1: SWOT natural landscape of Shadorvan. Source: the authors.
Out of the site In the site context
threats opportunities restrictions
Strong points
Falling quality of natural
visual effect of site for
indigested interferences.
Oscillation of the river water
surface for the irrigation
plans and dam constructions.
Linkage between
the existing natural
resources, and
historical & modern
context of the city
within the general
design.
Development of
green civic spaces
& making a green
corridor at the
perimeter of
Shadorvan dom-
bridge.
Free and isolated
edged near the site &
river.
Inappropriate
functions near
natural spaces.
River as a trash bin.
The Karooun river with
non-stop stream in the
site.
The strong stone-bed of
the river.
High ecological power
by sustainable and
unsustainable resources.
ecology
Landscape restoration “Landscape restoration is an economical concern, and is a valuable challenge among all the new
solutions for the environmental management.” (France, 2008. Preface). As a national heritage in an industrial
world, cultural and historical landscapes are bringing up changes in economy, environment and social
opportunities in the way that “the purpose of restoration has to be as consolidation of potential unity of the
artifact.” (Brandi, 1388: 41). Neglecting and inappropriate development of urban landscape, and also the ever-
increasing human interferences has had a strong impression on cultural heritage and landscape of ecological
society and mostly, the inappropriate decisions will threat the survival and continuity of these cultural heritages
(Table 2).
Table2: restoration of historical landmarks according to the theories of restoration
Source: www.dio.gov/Secretary . (of the interior standards)
The process consists primary measuring to preserve and restore the current
materials and situation which helps to avoid replacement of new materials and
structural methods.
preservation
To prepare a situation for using the historical site, or to restore, change and add.
Albeit these should not exceed the historical and antiquity features of the region.
rehabilitation
The act or process of describing the form, features and identity of a place,
according to the related historical period. The precess consists of eliminating the
later-added extensions/elements and restoring its lost features through time and
events.
restoration
The act or process of new construction of forms and landscape elements and
structure, aiming to create the closest similarity with a specific historical period
and placement it used to be in.
reconstruction
The principles of Natural landscape restoration: 1. To follow the sustainable development measures, extensively and within the whole landscape, without mere
emphasis on conservation regions. (Bell. 2007:410)
2. To restore & reconstruct the ecological values by methods of natural revival and reconstruction, modifying
operations, “constant and long term management of natural landscape & design in order to revive the health of
landscape and humanistic advantages.” (Motloch,2001: 211) (figure 2).
3. “Landscape design in order to achieve the best aesthetic experience” (Craul et al, 2008: 22) and to design as
the natural patterns. (Bell. ،2007: 297 ).
The Restoration of Shadorvan Dam-Bridge, Cultural & Historical Landmark of Shooshtar
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Figure2: Restoration of Shadorvan dom-bridge, 2013. Source: Fereshteh Taleb-Mashhadi.
The natural-historical landscape of Shadorvan Cultural-historical structures and monuments try to preserve the survival and values while keeping up with the
contemporary needs (by fixating the historical function or giving it the proper usable function). UNESCO world
heritage committee had offered a definition for the cultural landscape as the geographical distinction mark of the
lands: “A show combined of natural and humanistic monuments.” (Fowler, 2003: 15). In architecture and
urbanism, the historical landscape seems to be a brand new topic which has been listed in the world heritage
category for the contract signed in the UNESCO, and attracted the attention of countries. The cultural landscape
is a emanation field of nature and culture through time, supporting cultural and emotional functions as well as
physical ones while often has an appreciative cultural and positional identity. Certainly by the improvement of
technology and population & according to the diversity in human behavior patterns through time, the human
behavior -in any historical and cultural site- has been different. (Mokhles.2013: 4 ).
Shadorvan is a cultural-historical tale of the region, hence preserving it depends on protecting the natural ,
cultural and physical features of the region, simultaneously. Protecting these sites and analyzing the efforts that
have been done or are to be done, shall enhance the life quality and transmit the sense of place and identity
much better to the next generations. Shadorvan is a combined model for culture and nature of a society & its
development will cause a considerable increase in cultural exchanges.
The necessity of privacy for historical monuments “The old landscapes will not reemerge, but the ways to preserve and make sustainability of them along with
melting into modern life and taking advantage of their urban/landscape design principles are the issues that have
to be taken under consideration.” (Antrop, 2003).
The mere preserve and restoration is not the things that matter, however maybe sometimes only the restoration
will end up more sustainable and functional. The restoration must obey the proper function of the historical
monument which shall avoid its isolation and oblivion.
“The restoration, as we know today, does not date very back in time, although some cautious actions can be
tracked. But any restoration in order to keep the ancient monument is a modern act of the recent centuries.
Keeping the ancient models is an action that has several reasons & shall contain many values for human
societies.” (Motaghi. ،2009: 48 ).
In a world that undergoes quick changes, time and money used for restoring the ancient monuments because of
their inner value, keeping historical beauty & landscape, visual & tangible documentation, and also for artistic &
cultural sustainability. The aquatic system of Shooshtar is settled in a natural land, hence its restoration must
follow the natural situation of the region & the historical-natural relations to the surrounding elements. Therefor
establishing privacies seem mandatory –especially large scale civic programs such as building dikes. These
information must be verified by the organization during the Feasibility study process.
The Restoration of Shadorvan Dam-Bridge, Cultural & Historical Landmark of Shooshtar
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Figure 3: Shadorvan sanctum and arena. 1- Shadorvan dom-bridge. Source: Shooshtar detail design, 2005.
Merits for Shadorvan historical landscape restoration Proposals to achieve merits for preservation and restoration of Shadorvan historical landscape:
1. To record Shadorvan as a “cultural-historical landscape”: this can bring global credit for this region. This
shall assign a wider domain than the current UNESCO list. It will also lead to elimination of industries and low-
value buildings.
2. preservation plans: Studying archeology, we can use “preservation, restoration & reconstruction” (Feilden at
et 1998.82) plans to preserve and revive Shadorvan historical landscape.
Table 3: SWOT of preservation of Shadorvan cultural landscape. Source: the authors.
Out of the site In the site
threats opportunities restrictions Strong points preservation
1. reluctancy of
the residents to
restoration and
renovation of the
units adjacent to
the old context.
2. Weakness in
public financial
resources for city
development & its
effects on
preservation
project resources.
3. decrease in city
income rate
because of
restriction in
building projects
around the
preserved sites.
4. The possibility
of an increase in
water level which
may lead to flood
and demolition of
constructions.
1. Providing jobs
and income for the
citizens.
2. improve the
experimental and
technical
knowledge of the
workmen and
managers, in the
case of settling a
systematic
instructional
management for
restoration
projects.
1. Management
weak points in
scientific
restoration
methods & hasty
operations with
inappropriate
techniques.
2. general
ignorance about
the existing values
due to weak
informing system.
4. Inadequate
supervision and
operational
controls for
different parts of
the historical
landscape in order
to prevent any
interfering.
5. inadequate
budget for
restoration &
reconstruction.
1. To assign the
preservation limits
by the cultural
heritage
organization & to
make a technical
preservation
committee.
2. To keep the
main interface in
the city context
despite the
damages through
time.
3. To restore the
historical
landscape.
Necessity of reconstructing the Shadorvan dom-bridge The project is base dupon the idea of preservative restoration, and the purpose is to bring back the originality
and credit of the monument, without any change in its origin. This could be fulfilled by:
1. resolving the damages, frazzles, weathering, electrical cables, humanistic interferes and etc.
2. preventing any more damage and fortifying the structure.
3. providing a good sight and viewpoint for Shadorvan dom-bridge.
The Restoration of Shadorvan Dam-Bridge, Cultural & Historical Landmark of Shooshtar
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4. Providing a safe place in the city and removing abnormal behaviours close to the bridge.
5. Protecting the structure as a valuable heritage and preserving it for the following generations.
6. Preparing an organizing program: Unfortunately some plans and ideas have been performed without
dedicated studies, on the bridge and surrounding area that has destroyed the natural and historical sight. (figure
4)
To take back originality to the monument will make it as a dynamic element; also to insert dynamism to the
surrounding area will accelerate this achievement.
When we reach this purpose, we would be able to show off the power and intelligence of our ancestors and the
potentials of our vernacular structures. It will be a way to develop tourism and attract in-border and foreign
tourists. (Table 4).
Figure 4: Non-normative restoration of Shadorvan dom-bridge, 2013. Source: Fereshteh Tleb-Mashhadi.
Table 4: SWOT analysis table about historical landscape of shadorvan. Source: the authors.
Out of the system In the system context
threats opportunities restrictions facilities
Function of the site
1. To cause disturbance
for the natural &
humanistic landscape
by performing new
constructions around.
2. To create duality
between the the
restored and developed
context around the
historical site with the
old residential and non-
residential ones
throughout the city, in
the case of not having a
site plan.
3. To increase pressure
to the river and water
pollution.
1. To perform the
master plan of the
city by the
approach of taking
advantage of rich
resources of the
urban historical
and natural context.
2. Creating more
job opportunities
by constructing
tourist guest
centers.
3. Organizing the
other site-related
urban centers by
organizing the site
landscape.
1. lack of
transparency &
unity n the
construction merits -
offered by the
responsible
organizations,
around the ancient
district.
2. Erosion of the old
adjacent residential
context.
3. Insufficient
quality & quantity
of the urban
istallations and
equipments around
the site.
4. lack of services
and tourism
facilities.
5. The existance of
irrelevant structures
around the historical
context.
1. The assigned privacy
for Shadorvan Dom-
Bridge
2. Natural lndscape
along the river
3. Possibility of
creating a recreational
function for the public
use of citizens.
4. Possibility to release
the east side of the site
and refunctioning it for
preservation and green
land development &
tourism service.
The Restoration of Shadorvan Dam-Bridge, Cultural & Historical Landmark of Shooshtar
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Merits for natural-historical landscape of Shadorvan preservation Within the historical context of Shadorvan that indicates wide range of human-nature interrelation,
merits are assigned as follow:
Historical monuments for nations are documents of ancient glory –a witness on a great old civilization
remained up to the present time. These visible proofs could enhance to form a national-cultural identity and help
the human to remember memories in the place. They could bound the society of today with the past and hence,
form a special meaning to the present days. Having gained much recognition and significance since 1960s to
justify the historical landscape preservation, this attitude is in a direct relation with the contemporary
sensitivities, sociological index, and concept of individuality and builds a barrier against cultural
synchronizations. “The recommendation on beauty and landscape features‟ preservation 1962”, edited in the
1960s says: “Historical districts are heritages & their destructions will cause loss of serenity & also considered
as an abuse to social rights, even if it doesn‟t cause economical loss.” Contemporary human is more aware about
the importance of human values‟ unity and know the ancient monuments as a heritage for all, accordingly their
preservation is a general operation which in the most original way consists of every individual‟s corporation.
The most defensive reasons for different valuable aspects of historical monuments usually consist of aesthetic,
social and cultural values, rather that tangible economical & commercial ones. Although in today‟s living style,
to preserve and take use of structures and historical landscapes faces many challenges and economic crisis. We
must keep in mind that in the economically competitive world of today, the historical monuments are seen as
„produsts‟ which are rare, therefore, worthy. This feature of being rare and uncommon could raise financial
benefits as for tourism attraction or special social-cultural events. The results of studying the solutions for the
historical landscape preservation merits are documented in table 5.
Table 5: Methods of conservation and restoration of Shadorvan cultural landscape. Source: the authors.
solutions for the natural landscape of Shadorvan bridge preservation
1. To remove polluted water, “to prevent pollution in the focal point” (Botkin 2008: 418 ) and to
prevent sewage penetration into the river of Gargar.
2. Restoration of site & removing the desolated or architecturally worthless structures. (Craul et
al,2008: 22).
3. To preserve and restore earth and prevent soil drifting & erosion. Also to revive vernacular
vegetation.
4. To prevent constructions which are heterogeneous with the site.
solutions for the historical landscape of Shadorvan bridge preservation
1. To fortify the dignity of cultural heritage organization among civil decision-making institutions
& to define a fair budget for this organization for performing requested plans.
2. To fulfill fundamental & comprehensive studies on the natural-historical site for learning more
about the roots & processes of the complex configuration & also in order to gain dominancy on
sustainability aspects of it.
3. To provide and fulfill a purging plan of site and surrounding area, plus restorations according to
the sustainable preservation and development measures.
4. Ratification and performing comprehensive rules for urbanism and restoration according to
urban development plans, needs of the citizens, and coherent reservation of historical monuments
between civic institutions and Cultural Heritage Organization.
5. To encourage the owners of old rusty buildings for restoration and renovation according to the
declared measures, through encouraging policy.
6. To develop transportation and communication systems in & out of the city & to construct proper
roads and bridges.
Conclusion As a historical landscape, the Shadorvan dom-bridge area stands as a linkage between now and past; a
medium to helps human gain an acceptable fair cognition about his past and identity. So in the first place, people
would know the landscape and its identical-cultural values, and second, tries to preserve and transmit it to the
next generation. The harmony between a structure and its surrounding which is gained through decades and
centuries has a very high importance and as a basic principle should not ever be demolished. Also it is not
justified to demolish the area or make a transmission to build a single structure, just in case of instant
considerations.
To study the landscape of Shadorvan, its special identities and their interrelations, is an important
obligatory of present time. As a main stream of recreation and historical linkage between nature and urban
setting, Shadorvan dom-bridge had potentials which enroot in the pass of time. Although this cultural-historical
complex has been existed since very long time ago but up to now, its unique identity has never been the basis of
its special organization, hence, it is mandatory to study, know and preserve the identical, historical, cultural and
The Restoration of Shadorvan Dam-Bridge, Cultural & Historical Landmark of Shooshtar
www.ijlret.com 22 | Page
natural features of the monument for the sustainability of the landscape identity. Shadorvan (along with other
historical contexts of Shooshtar), through a historical relation between human and nature, offers a great potential
for sustainable development programs and define new standards for enhancement of living styles according to
the historical, cultural & tourism capacities. By precise and deep studies on the structural features of this
complex we shall create a harmonious corporation between human and nature.
Feuilleton
1- Preservation
2- Rehabilitation
3- Restoration
4- Reconstruction
Reference [1] Afshar Sistani E., Take Khuzestan, a collection of historical, social and economic. second edition.
Bolour of Press. 237(1987).
[2] Antrop M., way landscape of the past is important for the future. Location; Belgium. 126-
December(2003)
[3] Behbahani H et al., Take the protection and rehabilitation of archaeological perspective (Case Study
Takh_e Soleiman), Res. J. Recent Sci, Architecture of Iran. 3(12), 8-9(2007).
[4] Bell S., Landscape, Pattern, Perception and Process. Translated by: B. Aminzade. University of
Tehran2618. 287-289(2007).
[5] Brandi C., Theory of Restoration , Translated by Hanachi, b. University of Tehran press. 98(2013).
[6] Botkin D. Keller., E., Environmental Science. Translated by Vahabzade, A., University of Mashdad
press.217(2009).
[7] Craul P J. Rowe C L., Restoration of Drastically Disturbed Sites: Spectacle. Island Boston Harbor,
Hand-book of regenerative Landscape design. New Yourk: Taylor & Francis Group.17 (2008)
[8] Feilden B M. Jokilchto J. Management guidelines for world cultural heritage sites. Translated from
English by Hanachi P., Tehran: University of Tehran press. 86(1998).
[9] Fowler P J. World Heritage Cultural Landscapes 1992-2002. Paris: Unesco World Heritage Center.3
(2003).
[10] France R L.,. Handbook of Regenerative Landscape Design. New York: taylor & Francis Group.
19(2008)
[11] Minas S. Mozafar F ,et al ., Congress held today. Culture. Goldasteh of Esfahan Peress. 9( 2010)
[12] Mokhles F., Pyrmorad grave historical perspective ritual city of Baneh. Bagh_e Nazar, 10 (24). 27-
38(2013).
[13] Motaghi M., Shushtar Waterfalls of organizing infrastructure design environment. Master thesis.
University of Tehran. 107(2011).
[14] Motloch, J.. Introduction to Landscape Design. second edition. New York: John Wiley and sons, Inc.
78-79(2001).
[15] Pour Yousef Zade S.,. Restoration of historical and cultural perspective by emphasizing measures
Bisoton_e Kermanshah, Bagh_e Nazar, 9 (22), 35-44(2013).
[16] UNESCO Website.. ICOMOS (1992-2009). Available from: http://icorp.icomos.org.( 2009 ).
[17] Www.dio.gov/Secretary of the Interior Standards.
International Journal of Latest Research in Engineering and Technology (IJLRET)
ISSN: 2454-5031(Online)
www.ijlret.com ǁ Volume 1 Issue 1 ǁ June 2015 ǁ PP.23-29
www.ijlret.com 23 | Page
Sliding mode control of Vienna rectifier with output voltage
control
1Rouzbeh Reza Ahrabi,
2Mehdi Elmi,
3Mohammad Reza Banaei
Department of Electrical Engineering, AzarbaijanShahidMadaniUniversity, Tabriz, Iran
Abstract: In this paper, a Vienna type boost rectifier is discussed and controlled using sliding mode control.
Sliding mode control function is defined to control output. The object of this system is to provide desired output
DC voltage in any possible circumstances.
Introduction: Three-phase AC-DC power supplies (rectifiers) are widely used in many aspects of power systems, such as: 1)
High-voltage direct current (HVDC) systems; 2) Uninterruptible power supply (UPS); 3) Variable speed drives;
4) As generator side converter for permanent-magnet synchronous generator (PMSG) [1]. Conventional
rectifiers are known using diodes and thyristors to supply uncontrollable and controllable dc power. Current
harmonics are the most important problem of these converters, which causes lower power quality, and voltage
distortion. Another problem is the low power factor at input side of rectifiers. Several standards are issued to
prevent or decrease the mentioned problem such as IEEE-519, IEC555. In order to overcome the problems some
options were used, such as passive filters, active filters and hybrid filters. However, these options increase the
cost and losses of system which are good reasons to reduce efficiency of the converter [2]. Because of these
problems, AC-DC converters can be improved, using power switches and changing in the circuit diagram [3-8],
[2].Various AC-DC converters in terms of control system and circuit structure have been introduced up to now
[2], [9-11]. In [2] AC-DC converters are divided into five major groups Buck, Boost, Buck-Boost, Multilevel
and Multi-pulse. Each one of these converters can operate in unidirectional and bidirectional and in particular
goals with particular benefits. In [9] rectifiers are divided into two major groups; controlled and uncontrolled
rectifiers that each one of them is divided into isolated and non-isolated and at last each group appear in bridge
and full-wave. Power factor correction (PFC) of conventional rectifiers and passive diode rectifiers and
performance of the three phase buck type rectifier with PFC are studied in [10-11]. In addition, the essence of
four active three-phase PFC rectifiers (active six-switch boost-type PFC rectifier, the VIENNA rectifier, the
active six-switch buck-type PFC rectifier, and the SWISS Rectifier) are dedicated. Each one of these rectifiers
has positive and negative points in various applications. For example, the diode rectifiers with a boost converter
could regulate the output voltage and also improve the input power factor. If the input three-phase voltages are
unbalance, correcting the power factor may be one of problems. If the load is sensitive to voltage changes, so
the adjustment and balancing of rectifier's output voltage with poor control capability will problematic under
distortion and harmonic condition of utility side. Three-phase Vienna rectifier [7] with six diodes and three
bidirectional power switches is one of acceptable structures in PFC and boosting voltage, which is widely
discussed in recently published papers with promoting control policies [1], [12-17].One of the most important
benefit of Vienna rectifier is its capability to work under various distortions in input side such as harmonic
distortion and unbalance input voltages [18-19]. The introduced structures in [18-19] are three-phase three wires
which need to complicated control system under unbalance input voltage conditions. In [20] to avoid from
mentioned complication the Vienna rectifier for three-phase four wires system is proposed. The benefit of fourth
wire appears in unbalance and distorted input voltage to lead distortions into neutral point. Many control
methods have been introduced to control Vienna rectifier [4], [9] and [21]. These techniques are effective to
control Vienna rectifier in PFC and output voltage regulating. But it should be noted that under distorted input
voltage conditions control of the system is complicated. Sliding mode control (SMC) is one the methods, which
widely have been used in power electronic converters [22-28]. SM is an effective control method with high
frequency performance for nonlinear systems. It has some advantages such as simple implementation,
disturbance rejection, strong robustness, and fast responses, but the controlled state may exhibit undesired
chattering [29]. In this paper, sliding mode is used to control the three-phase four wires Vienna rectifier under
normal and distorted conditions of input voltage. Each phase of three-phase input is controlled individually in
order to make control easier and clear. In order to prevent chattering phenomena the fixed frequency SMC is
utilized.
Sliding mode control of Vienna rectifier with output voltage control
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System configuration Three-phase three wires and four wires Vienna rectifiers are illustrated in Fig. 1(a) and Fig. 1(b) respectively. In
this paper three-phase four wires Vienna rectifier is considered. In the normal condition VA, VB and VC are input
three-phase voltage and each phase has 120° phase shift in comparison to other phases. La, Lb and Lc are input
filter inductors. Sa, Sb and Sc are bidirectional power switches, insulated-gate bipolar transistor (IGBT) with
common emitter connection for each double switches.
VA
VB
VC
ia
ib
ic
La
Lb
Lc
DbuDau Dcu
DbdDad Dcd
Sa
Sb
S c
Cu
Cd
loa
d Vo
Vn
(a)
VA
VB
VC
ia
ib
ic
La
Lb
Lc
DbuDau Dcu
DbdDad Dcd
Sa
Sb
S c
Cu
Cd
loa
d Vo
VnVn
(b)
Fig. 1
a. Three-phase Vienna rectifier
b. Three-phase Vienna rectifier with connected fourth wire
Based on the presented structure in Fig. 1(b) the three phase system can be considered as 3 single phase system
without loss of generality and exclusive feature of rectifier. Fig. 2 show single-phase structure of Vienna
rectifier. Compensation scheme and control procedure will be executed on single-phase structure then it will be
generalized to three-phase system.
Vin
iinL
Lu
Ld
SC
u
Cd
loa
d Vo
VnVn g
Fig. 2 Single-phase Vienna rectifier
Converter performance
Vienna rectifier perform as boost AC-DC converter. In order to describe performance of the Vienna rectifier,
single-phase structure of AC-DC converter is considered as Fig. 2. Performance of the Vienna rectifier is
divided into two states which are shoot through and non-shoot through.
Sliding mode control of Vienna rectifier with output voltage control
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Shoot through In this state without noticing to input voltage phase, power switch Sgis turned on and AC current flows through
inductor L, power switch Sg and input voltage source. Fig. 3(a) shows shoot through state of Vienna rectifier,
which bidirectional power switch is turned on and diodes Lu and Ld are reverse biased.
Non-shoot through In this state power switchSgis turned off and diodes Lu and Ldare forward biased due to inductor current. Fig.
3(b) shows currents path in the non-shoot through.
Vin
iinL
Lu
d
Cu
Cd
loa
d Vo
VnVn
+_
+_
L
Sg
(a)
Vin
iinL
Lu
d
Cu
Cd
load Vo
VnVn
+_
+_
L
Sg
(b)
Fig. 3
a. Single-phase Vienna rectifier in shoot-through state
b. Single-phase Vienna rectifier in non-shoot-through state
Control scheme Control scheme is presented in order to combine with sliding mode control. Reference voltage is used by SMC
to balance the capacitor’s voltage.
Sliding mode control: Fig. 4 shows performance diagram of control system, which will merge with sliding mode in order to control the
Vienna rectifier.
+_
vref
vo
x1
Fig. 4 Diagram of control system
The sliding surface, S,is defined as:
Sliding mode control of Vienna rectifier with output voltage control
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1 1 2 2 3 3S x x x (4)
That α1, α2 and α3 are the sliding surfaceindexes. The logic state of power switch Sgis defined as follows:
1(1 sign(S))
2u (5)
where, u is switching function. In order to control Vienna rectifier with PFC and output voltage balancing
capabilities, the input current error x1, the output voltage error x2 and the integral of the voltage and current
errors x3 are considered as control variables which are expressed as:
ref ref o ref oi K v v K v v (6)
1
2
3 1 2
ref L
ref o
x i i
x v v
x x x dt
(7)
K is the gain of the voltage error. A large value for K is chosen to improve dynamic response and to minimize
the steady state voltage errors [30]. Dynamic model of Vienna rectifier based on Fig. 2 can be obtained as
follows:
.
1
.
2
.
3 1 2
ref L o i o
ref o o
ref o L ref o
d i i dv v uvx K
dt dt L
d v v dvx
dt dt
x x x K v v i v v
(8)
1u u is considered to be complementary logic of u. vi and vo are instantaneous input and output voltages. L
donates inductor of the converter. The equivalent control signal of the SM current controller when applied to the
Vienna rectifier is obtained by solving (9). . . .
1 2 31 2 3 0dS
x x xdt
(9)
which gives
3 3
1 1
32
1 1
o ref o
oL o i
uv v v L K L
dvLK Li v v
dt
(10)
where,
3 31
1 1
K L K L
(11)
22
1
K LK
(12)
33
1
K L
(13)
Considering vramp= uvo and replacing uvowithvr then we have
1 2 3o
r ref o L o i
dvv K v v K K i v v
dt (14)
ramp ov uv (15)
Sliding mode control of Vienna rectifier with output voltage control
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Because of fixed-frequency structure of presented SM controller, the chattering phenomenon, which is the
important drawbacks of nonlinear controllers, will be eliminated.
Simulation result In order to verify performance of the proposed SMC on three-phase Vienna rectifier Matlab/Simulink is done.
Simulations is operated in discrete mode with 1 µs step size. Parameters of Vienna rectifier are listed in Table I.
k, orthogonal systems bandwidth factor is 0.3. In this case the input signal consist of main harmonic with 20%
fifth harmonic, 5% seventh harmonic and 2% eleventh harmonic with 20.71% total harmonic distortion (THD).
Main harmonic appear with peak voltage of 100 (V) and the frequency is 50 (Hz). Fig. 5(a) shows the distorted
utility side voltage which supplies a Vienna rectifier and at 0.18 sec its fundamental component is increased up
to 50%. The output DC voltage of Vienna rectifier is shown in Fig. 5(b). It can be seen from this figure that the
output voltage remains constant in its reference value (500v) despite of input voltages changing.
Table I Tested system parameters
RLoad 150 (Ω)
L 1 (mH)
Vi(peak) 100 (V)
(a)
(c)
Fig. 8 Simulation results for three-phase grid connected Vienna rectifier with distorted input voltage (
Fundamental voltages are increased 50% at t = 0.18 s )
a. Grid side voltage
b. Output DC voltage
These results verify the proper performance of presented control system based on combination of SMC and
orthogonal systems.
Conclusion Sliding mode control is applied to Vienna rectifier. Output voltage is controlled and stabilized in desire voltage.
Despite of input distortions,output DC voltage is stabled on desire voltage that guarantee the performance of
control system.
0.1 0.14 0.18 0.22 0.26
-200
-100
0
100
200
Time (s)
1 1.4 1.8 2.2 2.6400
450
500
550
600
Time (s)
Sliding mode control of Vienna rectifier with output voltage control
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References [1]. Uzunoglu M, Kocatepe C, Yumurtaci R. Voltage stability analysis in the power systems including non-
linear loads. European Transactions on Telecommunications 2004; 14 : 41-56. DOI: 10.1002/etep.5
[2]. Rajaei A, Mohamadian M, YazdianVarjani A. Vienna-Rectifier-Based Direct Torque Control of PMSG
for Wind Energy Application. IEEE Transactions on Industrial Electronics 2013; 60: 2919-2929. DOI:
10.1109/TIE.2012.2227905
[3]. Singh Bhim, Singh B.N, Chandra A, Al-Haddad K, Pandey A, Kothari D.P. A review of three-phase
improved power quality AC-DC converters. IEEE Transactions on Industrial Electronics 2004; 51: 641-
660. DOI: 10.1109/TIE.2004.825341
[4]. Grbovic P.J, Delarue P, Le Moigne P. A Novel Three-Phase Diode Boost Rectifier Using Hybrid Half-
DC-Bus-Voltage Rated Boost Converter. IEEE Transactions on Industrial Electronics 2011; 58: 1316-
1329. DOI: 10.1109/TIE.2010.2050757
[5]. Kolar J.W, Ertl H, Zach F.C. Space vector-based analytical analysis of the input current distortion of a
three-phase discontinuous-mode boost rectifier system. IEEE Transactions on Power Electronics 1995;
10: 733-745.DOI: 10.1109/63.471293
[6]. Mohan N, Rastogi M, Naik R. Analysis of a new power electronics interface with approximately
sinusoidal 3-phase utility currents and a regulated DC output. IEEE Transactions on Power Delivery
1993; 8: 540-546. DOI: 10.1109/61.216857
[7]. Kolar J.W, Drofenik U, Zach Franz C. VIENNA rectifier II-a novel single-stage high-frequency isolated
three-phase PWM rectifier system. IEEE Transactions on Industrial Electronics 1999; 46: 674-691. DOI:
10.1109/41.778214
[8]. Kanaan H, Al-Haddad K, Chaffai R, Duguay L, Fnaiech F. A new low-frequency state model of a three-
phase three-switch three-level fixed-frequency PWM rectifier. Telecommunications Energy Conference
2001; Twenty-Third International: 384-391 DOI: 10.1049/cp:20010626
[9]. Nishimoto M, Dixon Juan W, Kulkarni Ashok B, Ooi Boon-Teck. An Integrated Controlled-Current
PWM Rectifier Chopper Link for Sliding Mode Position Control. IEEE Transactions on Industry
Applications 1987; IA-23: 894-900. DOI: 10.1109/TIA.1987.4505000
[10]. Singh B, Gairola S, Singh B.N, Chandra A, Al-Haddad K. Multipulse AC–DC Converters for Improving
Power Quality: A Review. IEEE Transactions on Power Electronics 2008; 23: 260-281. DOI:
10.1109/TPEL.2007.911880
[11]. Kolar J.W, Friedli T. The Essence of Three-Phase PFC Rectifier Systems—Part I. IEEE Transactions on
Power Electronics 2013; 28: 176-198. DOI: 10.1109/TPEL.2012.2197867
[12]. Friedli T, Hartmann M, Kolar J.W. The Essence of Three-Phase PFC Rectifier Systems—Part II. IEEE
Transactions on Power Electronics 2014; 29: 543-560. DOI: 10.1109/TPEL.2013.2258472
[13]. Ming Z, Lijun H, Wenxi Y, Zhengyu L, Tolbert L.M. A Novel Strategy for Three-Phase/Switch/Level
(Vienna) Rectifier Under Severe Unbalanced Grids. IEEE Transactions on Industrial Electronics 2013;
60: 4243-4252. DOI: 10.1109/TIE.2012.2217721
[14]. HaoCh, David N, Aliprantis D.C. Analysis of Permanent-Magnet Synchronous Generator With Vienna
Rectifier for Wind Energy Conversion System. IEEE Transactions on Sustainable Energy 2013; 4: 154-
163. DOI: 10.1109/TSTE.2012.2208660
[15]. Lijun H, Ming Z, Tolbert L.M, Zhengyu L. Digitized Feedforward Compensation Method for High-
Power-Density Three-Phase Vienna PFC Converter. IEEE Transactions on Industrial Electronics 2013;
60: 1512-1519. DOI: 10.1109/TIE.2012.2222851
[16]. Cheng Wa, Meng H, Tse C.K, Siu-Chung W, Xinbo R. Nonlinear Behavior and Instability in a Three-
Phase Boost Rectifier Connected to a Nonideal Power Grid With an Interacting Load. IEEE Transactions
on Power Electronics 2013; 28: 3255-3265. DOI: 10.1109/TPEL.2012.2227505
[17]. Friedli T, Hartmann M, Kolar J.W. The Essence of Three-Phase PFC Rectifier Systems—Part II.IEEE
Transactions on Power Electronics 2014; 29: 543-560. DOI: 10.1109/TPEL.2013.2258472
[18]. Liu S, Hang L, Zhang M. Natural frame-based strategy for vienna-type rectifier with light unbalanced
input voltages. IET Power Electronics 2013; 6: 1427-1435. DOI: 10.1049/iet-pel.2012.0612
[19]. Lijun H, Bin L, Ming Z, Yong W, Tolbert L.M. Equivalence of SVM and Carrier-Based PWM in Three-
Phase/Wire/Level Vienna Rectifier and Capability of Unbalanced-Load Control. IEEE Transactions on
Industrial Electronics 2014; 61: 20-28 DOI: 10.1109/TIE.2013.2240637
[20]. Zhang X, Fan C. Research on 3-Phase 4-Wire VIENNA Rectifier Based on One Cycle Control.
Intelligent Computation Technology and Automation (ICICTA) 2012; Fifth International Conference
on:280-282. DOI: 10.1109/ICICTA.2012.77
[21]. Hartmann M, Miniboeck J, Kolar J.W. A Three-Phase Delta Switch Rectifier for More Electric Aircraft
Applications Employing a Novel PWM Current Control Concept. Applied Power Electronics Conference
and Exposition APEC 2009; Twenty-Fourth Annual IEEE: 1633-1640. DOI:
10.1109/APEC.2009.4802887
Sliding mode control of Vienna rectifier with output voltage control
www.ijlret.com 29 | Page
[22]. Sanchis P, Ursaea A, Gubia E, Marroyo L. Boost DC-AC inverter: a new control strategy. IEEE
Transactions on Power Electronics 2005; 20: 343-353. DOI: 10.1109/TPEL.2004.843000
[23]. Pinheiro H, Martins A.S, Pinheiro J.R. A sliding mode controller in single phase voltage source inverters.
Industrial Electronics Control and Instrumentation 1994; 1: 394-398. DOI: 10.1109/IECON.1994.397810
[24]. Oucheriah S, Liping G. PWM-Based Adaptive Sliding-Mode Control for Boost DC–DC Converters.
IEEE Transactions on Industrial Electronics 2013; 60: 3291-3294. DOI: 10.1109/TIE.2012.220376
[25]. Shtessel Y, Baev S, Biglari H. Unity Power Factor Control in Three-Phase AC/DC Boost Converter
Using Sliding Modes. IEEE Transactions on Industrial Electronics 2008; 55: 3874-3882. DOI:
10.1109/TIE.2008.2003203
[26]. Majid N, Mohammad Rasoul N, Taher N, Shahrokh J. Design of sliding mode controller for
UPFC to improve power oscillation damping. Applied Soft Computing 2011; 11: 4766–4772. DOI:
10.1016/j.asoc.2011.07.006
[27]. Malesani L, Spiazzi R.G, Tenti P. Performance optimization of Cuk converters by sliding-mode control.
IEEE Transactions on Power Electronics 1995; 10: 302-309. DOI: 10.1109/63.387995
[28]. Il-Song K. Robust maximum power point tracker using sliding mode controller for the three-phase grid-
connected photovoltaic system. Solar Energy 2007; 81: 405-414. DOI: 10.1016/j.solener.2006.04.005
[29]. Jiabing H, Heng N, Bin H, Yikang H, Zhu Z.Q. Direct Active and Reactive Power Regulation of DFIG
Using Sliding-Mode Control Approach. IEEE Transactions on Energy Conversion 2010; 25: 1028-1039.
DOI: 10.1109/TEC.2010.2048754
[30]. Ciobotaru M, Teodorescu R, Blaabjerg F. A New Single-Phase PLL Structure Based on Second Order
Generalized Integrator. Power Electronics Specialists Conference 2006; PESC '06: 18-22. DOI:
10.1109/PESC.2006.1711988
[31]. Fossas E, Martinez L, Ordinas J. Sliding mode control reduces audiosusceptibility and load perturbation
in the Cuk converter. IEEE Transactions on Circuits and Systems I: Fundamental Theory and
Applications 1992; 39: 847-849. DOI: 10.1109/81.199870
[32]. Martinez-Salamero L, Calvente J, Giral R, Poveda A, Fossas E. Analysis of a bidirectional coupled-
inductor Cuk converter operating in sliding mode. IEEE Transactions on Circuits and Systems I:
Fundamental Theory and Applications 1998; 45: 355-363 DOI: 10.1109/81.669058
[33]. Siew-Chong Tan, Lai Y.M, Tse C.K.A unified approach to the design of PWM-based sliding-mode
voltage controllers for basic DC-DC converters in continuous conduction mode. IEEE Transactions on
Circuits and Systems I: Regular Papers 2006; 53: 1816-1827. DOI: 10.1109/TCSI.2006.879052
International Journal of Latest Research in Engineering and Technology (IJLRET)
ISSN: 2454-5031(Online)
www.ijlret.com ǁ Volume 1 Issue 1 ǁ June 2015 ǁ PP.30-36
www.ijlret.com 30 | Page
Basics Of Kalman Filter And Position Estimation Of Front Wheel
Automatic Steered Robot Car
Muqri Muzammil, Prashant Bhopal, Yogesh Jain
Department of Electrical Engineering
Veermata Jijabai Technological Institute
Mumbai, India
Abstract— In this paper, we have described the coordinate (position) estimation of automatic steered car by
using kalman filter and prior knowledge of position of car i.e. its state equation. The kalman filter is one of the
most widely used method for tracking and estimation due to its simplicity, optimality, tractability and
robustness. However, the application to non linear system is difficult but in extended kalman filter we make it
easy as we first linearize the system so that kalman filter can be applied. Kalman has been designed to integrate
map matching and GPS system which is used in automatic vehicle location system and very useful tool in
navigation. It takes errors or uncertainties via covariance matrix and then implemented to nullify those
uncertainties. This paper reviews the motivation, development, use, and implications of the Kalman Filter.
Index Terms—Kalman Filter(KF),Extended Kalman Filter(EKF), Unscented Kalman Filter(UKF).
I. INTRODUCTION The main objective of any on road Automatic Vehicle system is that It should be navigated with route
information properly to the benefit of the user by relating vehicle location to its surrounding .To be effective, the
vehicle's position must be continuously maintained in real-time as position of automatic system changes with the
time.
Currently there are many techniques available for positioning of automatic vehicle location system, such as
(odometer and compass technique). But these techniques are not reliable (dead reckon) techniques [1],[2] and
[3] because they require updates to overcome the disturbance which comes into the picture with time and
distance. In odometer [4], fixed objects in the surrounding provide landmarks which are listed in a data base.
The system calculates the angle to each landmark and then orients the camera. A Kalman Filter is used to
correct the position and orientation of the vehicle from the error between the observed and estimated angle to
each landmark. Also to overcome the limitation of GPS technique it will be used combined with map matching
but it also has drawback with congested road and overcrowded building area. In this paper we are highlighting
the significance of kalman Filter in automatic vehicle location system.
Rudolf E. Kalman gave the idea of kalman filter, the great use Kalman filter is due to its small computational
requirement, recursive properties, and its status as the optimal estimator for non linear and linear systems with
Gaussian error statistics [5]. Typical uses of the Kalman filter include smoothing noisy data and providing
estimates of parameters of interest. Applications include global positioning system receivers, motors, robot and
many more.
A. PROCESS MODEL OF THE SYSTEM
The Kalman filter model assumes that the state of a system at a time k evolved from the prior state at time k-1
according to the equation
X (k) = A (k) x (k-1) + B (t) u (k) + w (k) (1)
Where
X(k) is the state vector containing the terms of interest for the system
(e.g., position, velocity, heading) at Time k.
U (k) is the vector containing any Control inputs (steering angle, throttle Setting, braking force).
A (k) is the state transition matrix which applies the effect of each system state parameter at time k-1 on the
system state at time k (e.g., the position and velocity at time k-1 both affect the position at time k).
Basics Of Kalman Filter And Position Estimation Of Front Wheel Automatic Steered Robot Car
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B (k) is the control input matrix which applies the effect of each. control input parameter in the vector u (k)
on the state vector (e.g., applies the effect of the throttle setting on the system velocity and position).
W (k) is the vector containing the process noise terms for each parameter in the state vector. The process
noise is assumed to be drawn from a zero mean multivariate normal distribution with covariance given by
the covariance matrix Q (k).
B. Measurement Model Of The System
Y (k) = C (k) x (k) + v (k) (2)
Where
Y (k) is the vector of measurements
C (k) is the transformation matrix that maps the state vector parameters into the measurement domain.
V (k) is the vector containing the measurement noise terms for each
observation in the measurement vector. Like the process noise, the measurement noise is assumed to be zero
mean Gaussian white noise with covariance R (k).
II.KAMAN FILTER ALGORITHM Kaman filter complete its operation in three stages.
1.It predicts the system evolution by using prior knowledge in (k-1).
2. It measures the output in time (k).
3. It update measured output in time (k).
Kalman filter assumes that all predicted posterior density point at ever time step is Gaussian function and hence
it is parameterized by mean and covariance.
A. Propagation stage
𝑋 (k+1)/ (k) =A(k) 𝑋 (k) (3)
P (k+1)/ (k) =A P (k)/(k) 𝐴𝑇 + Q (4)
And
[𝜔(𝑘)𝜔(𝑘)𝑇] = 𝑸
B. Measurement Stage
Y (k) = C (k) x (k) + v (k) (10)
C. Correction and Update Stage
K (𝑘+1)=𝑷(𝑘+1)/(𝑘)𝐶𝑇[𝐶𝑷(𝑘+1)(𝑘) CT]+R−1 …………………(11)
P (𝑘+1)/(𝑘+1) =(𝑰−𝑲(𝑘+1)𝐶)𝑷(𝑘+1)/(𝑘) …………………..(12)
X (𝑘+1)/(𝑘+1) =[X (𝑘+1)/(𝑘) +𝑲(𝑘+1)(𝑌(𝑘)−𝐶 X (𝑘+1)/(𝑘))] …………………………….(13)
So by introducing the term kalman gain K we can update our predicted equation i.e. whatever will be the error
in these equation can be compensated by selecting computing the kalman gain from measurement.
D. Recursive Kalman Gain
Basics Of Kalman Filter And Position Estimation Of Front Wheel Automatic Steered Robot Car
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III. Types Of Kalman Filter A. Extended Kalman Filter (EKF)
As we know no system in practical world is linear, In extended kalman filter, we need to first linearize the
system by taking the jacobian of state transition matrix(A) and measurement matrix (C) then we apply operation
of prediction and filtering.
EKF for nonlinear processes
Prediction Step
X (k+1)/(k)=X (k)/(k)+ 𝑓(𝑥 𝜏 , 𝑢𝑘)𝑑𝜏(𝑘+1)𝛥𝑡
𝑘𝛥𝑡 (14)
Covariance Matrix
P (k+1)/ (k) =A(k) P (k)/(k) 𝐴𝑇(𝑘) + Q(k) (15)
Correction Step
X (𝑘+1)/(𝑘+1) =[X (𝑘+1)/(𝑘) +𝑲(𝑘+1)(𝑌(𝑘)−g X (𝑘+1)/(𝑘))]
………….(16)
Problems with EKF
1. Uses linearized model[6] and[7] for computing covariance matrix (uncertainty) in estimates
2. Uses a linear estimator for obtaining updated estimates
3. Unconstrained estimator – Clipping has been adopted as a possible approach for including constraints.
4. Has been shown to generate poor estimates
5. Lengthy periods of over or under estimation, demonstrated in some cases to be 2 orders of magnitude.
B. Unscented Kalman Filter (UKF)
In unscented kalman filter, we don‟t need to linearize the system. We predict the pdf by sigma point approach
[6] and calculate their weighted mean and covariance. On the basis of their weighted mean and covariance we
select appropriate point. If „n‟ is an order of system then we select 2n+1 sigma point [8].
2n+1 sigma point selection
X0= X W0= (k)/ (k+n) (17)
Xi= X + ((𝑛 + 𝑘)𝑃𝑥𝑥 )i Wi= 1/2(k+n) ………(18)
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And
Xi+n= X _ ((𝑛 + 𝑘)𝑃𝑥𝑥 )i Wi+n = 1/2(k+n) ………(19)
2n+1 sigma points are propagated as
Yi=g (Xi) (20)
Mean is calculated
Y = 𝑊𝑖𝑌𝑖2𝑛𝑖=0 (21)
Covariance is calculated
Pyy = 𝑊𝑖[𝑌𝑖_𝑌 ][𝑌𝑖_𝑌 ]𝑇2𝑛𝑖=0 (22)
IV. Problem statement
Front-wheel steered robot modified:
States: x: x co-ordinate,
y: y co-ordinate,
ψ∶ heading angle,
α: steering angle,
v: velocity
Model:
State equations:
𝑥𝑦ψ
α
v
=
𝑣 cos ψ
𝑣 sin ψ
𝑣 tan α 0.005
0.098𝑒−𝑡
5
Output: z = 𝑥𝑦
Initial conditions: [0, 0, 0, 0, 0], t =[0, 15]
Basics Of Kalman Filter And Position Estimation Of Front Wheel Automatic Steered Robot Car
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For some navigation application, we need to know the precise position of vehicles when it turns, for using GPS
along with map matching system we need appropriate updated position of car so if vehicle misses its position
i.e. the desired trajectory then kalman filter will remove the error and take vehicle onto its desired trajectory. For
automatic vehicle system it is very important that it must know its location so that it may operate autonomously
and reach the required destination.
In this problem we have to find the position of car as we have been given the state equation (Process model)
and output measurement equation. In process model there are total five parameter. First two parameter x and y
are for coordinates of a car i.e. position of the car. Ψ is heading angle which changes w.r.t steering angle α. In
process model we can clearly see that position of car is dependent on the velocity v and the heading angle ψ, but
in this problem our aim to predict and update the position of the car(x and y coordinate) as shown in
measurement equation.
If we implement this problem using extended kalman filter (EKF), we need to linearize the matrix „A‟ by taking
its jacobian, then predict the position. If we take Unscented kalman filter (UKF) then no need for linearization,
we will predict the sigma point depend on the order of the process model. In our problem the order of the system
is 5 then UKF will predict 6 point [8]and out of them it will select 1 point on the basis of their weighted mean
and covariance and then filtering operation.
Initially we will consider variance matrix „w‟ as null matrix therefore our initial covariance matrix will also be
null matrix
Q = 0 ⋯ 0⋮ ⋱ ⋮0 ⋯ 0
Order of matrix depend upon the parameter of process model.
EkF Implementation Because of the nonlinear case that is encountered here we also have used an EKF that linearizes the current
mean and covariance. The EKF has been applied to the same robot model as the one used for the KF case. The
EKF algorithm is described in the following:
A. The prediction step:
By using procees model we will predict the next step.
𝑥𝑦ψ
α
v
=
𝑣 cos ψ
𝑣 sin ψ
𝑣 tan α 0.005
0.098𝑒−𝑡
5
First linearize it by taking its jacobian
J=
0 0 −𝑣𝑠𝑖𝑛ψ
0 0 𝑣𝑐𝑜𝑠ψ
0 0 0
0 00 0
𝑣𝑙𝑜𝑔𝑠𝑖𝑛α 𝑡𝑎𝑛α
0 0 00 0 0
0 0 0 0
Where J is the jacobian of „F‟.
From output equation we have been given C=[1 1 0 0 0] which is Clearly indicating that we have to predict and
measure the coordinate of the car i.e the position of the car.
B. Observation and update:
In this step we need to compute the Kalman gain
Refer equation (11),(12) and(13)
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Result
Fig 2:EKF Result for time period t=0.5
On x-axis t in second ,
Fig 3:EkfF Result fortime period t=0.7
On x-axis t in second
Y-axis x_estimated in red and x_true in blue
On x-axis t in second
Y-axis x_estimated in red and x_true in blue
Conclusion We have presented the basic of kalman filter and successfully implemented the kalman filter on front wheel
automatic steered robot and got the results in scilab, as it is clearly showing on y-axis that x_estimated in (blue
line) updated by kalman filter and bringing it back to the x_true in (red line) by compensating the posterior
covariance.
Basics Of Kalman Filter And Position Estimation Of Front Wheel Automatic Steered Robot Car
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By making use of klaman filter together with GPS and map matching technique we can use it in automatic
vehicles for trajectory tracking.
Reference [1]. Edward J. Krakiwsky, Clyde B. Harris, and Richard V.C. Wong IEEE ,Map Matching And GPS
Positioning, by Department of Surveying Engineering The University of Calgary Calgary, Canada, T2N
1N4 1988.
[2]. Krakiwsky, E. J., Karimi, H. A., Harris, C. B.and George, J., (1987). Research into Electronic Maps and
Automatic Vehicle Location. Eighth International Symposium on Computer - Assisted Cartography. Auto
Carto 8, Baltimore, Maryland, U.S.A., March 29 (1987). .
[3]. French, R. L.,. Automobile Navigation: Where Is It Going? IEEE Position Location And Navigation S ~
~ DiumO. [SPL ANS '861, Las Vegas. NV., U.S.A. November 4-7. (1986).
[4]. Fddric Chenavier James L. Crowley, Position Estimation of a Mobile Robot Using Vision and
Odometry, 1992 international conference on robotics and automation, France- May 1992
[5]. M. Sanjeev Arulampalam, Simon Maskell, Neil Gordon, and Tim Clapp, A Tutorial on Particle Filters for
Online Nonlinear/Non-Gaussian Bayesian Tracking, IEEE Transaction On Signal Processing, Vol. 50,
NO. 2, February 2002
[6]. Simon J. Julier, Unscented Filtering and Nonlinear Estimation,Proceeding Of The Ieee, Vol. 92, NO. 3
March 2004.
[7]. P. J. Costa, “Adaptive model architecture and extended Kalman–Bucy filters,” IEEE Trans. Aerosp.
Electron. Syst., vol. 30, pp.525–533, Apr. 1994.
[8]. R. van der Merwe, Sigma-point Kalman Filters for Probabilistic Inference in Dynamic State-space
Models. Phd Thesis, OGI School of Science & Engineering – Orgon Health Science University, 2004.
[9]. K. Zhang, X. R. Li, and Y. Zhu, Optimal update with out-of-sequence measurements. IEEE Trans. Sig.
Proc., 53(6):1992-2004,2005.
[10]. R. E. Kalman, “A new approach to linear filtering and prediction problems,” J. Basic Eng., vol. 82, no.1,
pp. 35–45, Mar. 1960.